The 22nd Amendment bars any president from serving more than two full terms in office. It was passed by Congress in 1947 and ratified in 1951 as a reaction to Franklin Delano Roosevelt’s four-term presidency.

Amending the Constitution would require the approval of both the House and Senate and three-fourths of the states.

Former President Bill Clinton has frequently spoken out in favor of allowing presidents to serve more than two terms, provided they take some time off before running for a third time.

“I’ve always thought that should be the rule,” Clinton said in November. “I think as a practical matter, you couldn’t apply this to anyone who has already served, but going forward, I personally believe that should be the rule.”